A Warsaw-based convenience store chain is part of a lawsuit filed Tuesday seeking to lift the ban on cold beer being sold at gas stations in Indiana. The Indiana Petroleum Marketers and Convenience Store Association filed the suit in U.S. District Court in Indianapolis, arguing that the law is arbitrary and discriminatory against convenience stores. It was filed on behalf of Freedom Oil Inc., which owns six Freedom Express stores in Kosciusko and Marshall counties, as well as Ricker Oil Co. of Anderson and Thorntons Inc. of Louisville, Ky. The suit argues that there is no legitimate purpose for the cold beer restriction, and that Indiana loses tax revenue when residents drive across the state line to buy cold beer. Indiana Attorney General Greg Zoeller will argue that the law reflects the wishes of state lawmakers, according to the Associated Press. It was a lawsuit 20 years in the making, Freedom Oil owner Gregg Cobb said this morning. He said convenience stores have a long history of fighting state alcohol laws, which he described as backwards and, in the case of the cold beer ban, unconstitutional. The ban goes back to a 1963 law allowing liquor stores to sell chilled beer, while convenience stores can only sell chilled wine and warm beer. It took convenience stores 25 years to win recognition as grocery stores and be able to sell alcohol, he noted. “The consumer basically pays a premium because liquor stores have a monopoly. We just don’t think that’s fair to the general public,” Cobb said. He said the law is wrong to regulate a product by temperature, which the lawsuit points out that Indiana is the only state to do. “You don’t have to have a special license to buy a hot sandwich at Subway,” he remarked. “It’s like a law against convenience stores selling anything but leaded gasoline but allowing Kroger to sell premium.” He also criticised the law for allowing convenience stores to sell chilled wine, a product with a 12.5 percent alcohol content, but not chilled beer, with 4 percent alcohol. “Now that’s silly too,” he said. The Kosciusko County Alcoholic Beverage Commission has shown reserve similar to the state, expressing an unwillingness to grant licenses to gas stations. Cobb contended that a common argument against selling ready-to-drink beer at gas stations, that it enables drunk driving, ignores the fact that people drive to liquor stores too. “In my 30 years of being able to buy alcohol, I’ve only walked to the liquor store once,” he said. “I’ve never seen anybody who has walked to the liquor store, they all drive. So what’s the difference whether they’re filling their tank or not.” The lawsuit names the state, the Indiana Alcohol and Tobacco Commission and its chairman, Alex Huskey, as defendants and seeks declaratory judgment and injunctive relief. ‘‘In reviewing the history, it became more and more clear to us there really was not a rational basis for the current law,’’ said Scot Imus, executive director of the convenience store association that filed the suit, according to the Associated Press. ‘‘The fact the law says pharmacies, convenience stores and grocery stores are capable enough to sell the product warm, then it gets rather arbitrary about what temperature it can be sold at. When you change the temperature, it doesn’t change the alcohol content.’’